| 1 | ## oils_failures_allowed: 1
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| 2 | 
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| 3 | #### /^.$/
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| 4 | shopt -s ysh:all
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| 5 | var pat = ''
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| 6 | 
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| 7 | setvar pat = /^.$/
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| 8 | echo pat=$pat
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| 9 | 
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| 10 | setvar pat = /%start dot %end/
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| 11 | echo pat=$pat
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| 12 | 
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| 13 | if ('' ~ pat) {  # ERE syntax
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| 14 |   echo yes
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| 15 | } else {
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| 16 |   echo no
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| 17 | }
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| 18 | # $pat is same as pat
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| 19 | if ('f' ~ pat) {  # ERE syntax
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| 20 |   echo yes
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| 21 | } else {
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| 22 |   echo no
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| 23 | }
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| 24 | 
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| 25 | ## STDOUT:
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| 26 | pat=^.$
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| 27 | pat=^.$
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| 28 | no
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| 29 | yes
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| 30 | ## END
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| 31 | 
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| 32 | 
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| 33 | #### /.+/
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| 34 | shopt -s ysh:all
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| 35 | 
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| 36 | var pat = /.+/
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| 37 | echo $pat
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| 38 | 
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| 39 | var s = 'foo'
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| 40 | if (s ~ pat) {  # ERE syntax
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| 41 |   echo yes
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| 42 | }
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| 43 | var empty = ''
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| 44 | if (empty ~ pat) { echo yes } else { echo no }
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| 45 | ## STDOUT:
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| 46 | .+
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| 47 | yes
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| 48 | no
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| 49 | ## END
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| 50 | 
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| 51 | #### Repeat {1,3} etc.
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| 52 | var pat = null
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| 53 | 
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| 54 | setvar pat = /d{2}/
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| 55 | echo $pat
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| 56 | setvar pat = /d{1,3}/
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| 57 | echo $pat
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| 58 | setvar pat = /d{1,}/
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| 59 | echo $pat
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| 60 | setvar pat = /d{,3}/
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| 61 | echo $pat
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| 62 | 
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| 63 | 
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| 64 | ## STDOUT:
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| 65 | [[:digit:]]{2}
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| 66 | [[:digit:]]{1,3}
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| 67 | [[:digit:]]{1,}
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| 68 | [[:digit:]]{,3}
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| 69 | ## END
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| 70 | 
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| 71 | 
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| 72 | #### d+  digit+  !d+  !digit+
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| 73 | shopt -s ysh:all
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| 74 | 
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| 75 | var pat = ''
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| 76 | 
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| 77 | setvar pat = /d+/
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| 78 | echo $pat
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| 79 | if ('42' ~ pat) { echo yes }
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| 80 | 
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| 81 | var empty = ''
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| 82 | if (empty ~ pat) { echo yes } else { echo no }
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| 83 | 
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| 84 | setvar pat = /digit+/
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| 85 | echo $pat
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| 86 | setvar pat = /!d+/
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| 87 | echo $pat
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| 88 | setvar pat = /!digit+/
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| 89 | echo $pat
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| 90 | 
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| 91 | 
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| 92 | ## STDOUT:
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| 93 | [[:digit:]]+
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| 94 | yes
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| 95 | no
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| 96 | [[:digit:]]+
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| 97 | [^[:digit:]]+
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| 98 | [^[:digit:]]+
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| 99 | ## END
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| 100 | 
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| 101 | #### Alternation and sequence
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| 102 | var pat = ''
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| 103 | setvar pat = /s d+ | w*/
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| 104 | echo $pat
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| 105 | setvar pat = /s d+ or w*/
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| 106 | echo $pat
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| 107 | ## STDOUT:
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| 108 | [[:space:]][[:digit:]]+|[[:alpha:][:digit:]_]*
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| 109 | [[:space:]][[:digit:]]+|[[:alpha:][:digit:]_]*
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| 110 | ## END
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| 111 | 
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| 112 | #### Char Class Ranges
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| 113 | shopt -s ysh:all
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| 114 | 
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| 115 | var pat = ''
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| 116 | setvar pat = /[0-9 a-f]+/
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| 117 | echo $pat
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| 118 | # This is equivalent
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| 119 | setvar pat = /['0' - '9' 'a' - 'f']+/
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| 120 | echo $pat
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| 121 | 
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| 122 | if ('0123' ~ pat) { echo yes } else { echo no }
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| 123 | if ('zzz' ~ pat) { echo yes } else { echo no }
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| 124 | if ('' ~ pat) { echo yes } else { echo no }
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| 125 | ## STDOUT:
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| 126 | [0-9a-f]+
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| 127 | [0-9a-f]+
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| 128 | yes
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| 129 | no
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| 130 | no
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| 131 | ## END
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| 132 | 
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| 133 | #### Char Class Set
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| 134 | shopt -s ysh:all
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| 135 | var pat = ''
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| 136 | 
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| 137 | # This is NOT allowed
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| 138 | # setvar pat = /[a b c]+/
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| 139 | 
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| 140 | setvar pat = /['abc']+/
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| 141 | echo $pat
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| 142 | 
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| 143 | if ('cbcb' ~ pat) { echo yes } else { echo no }
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| 144 | if ('0123' ~ pat) { echo yes } else { echo no }
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| 145 | if ('' ~ pat) { echo yes } else { echo no }
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| 146 | ## STDOUT:
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| 147 | [abc]+
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| 148 | yes
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| 149 | no
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| 150 | no
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| 151 | ## END
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| 152 | 
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| 153 | #### Range with escaped characters
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| 154 | shopt -s ysh:all
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| 155 | 
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| 156 | var pat = null
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| 157 | 
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| 158 | setvar pat = / [ \x00 - \x0f ] /
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| 159 | echo $pat | od -A n -t x1
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| 160 | 
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| 161 | ## STDOUT:
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| 162 |  5b 00 2d 0f 5d 0a
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| 163 | ## END
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| 164 | 
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| 165 | 
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| 166 | #### Group ()
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| 167 | shopt -s ysh:all
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| 168 | var pat = ''
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| 169 | 
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| 170 | setvar pat = /(%start s or d d)/
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| 171 | echo $pat
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| 172 | 
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| 173 | if (' foo' ~ pat) { echo yes } else { echo no }
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| 174 | if ('-00-' ~ pat) { echo yes } else { echo no }
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| 175 | if ('foo' ~ pat) { echo yes } else { echo no }
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| 176 | 
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| 177 | ## STDOUT:
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| 178 | (^[[:space:]]|[[:digit:]][[:digit:]])
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| 179 | yes
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| 180 | yes
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| 181 | no
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| 182 | ## END
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| 183 | 
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| 184 | #### Capture is acceptable as a group
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| 185 | shopt -s ysh:all
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| 186 | var pat = /<capture %start s | d d>/
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| 187 | echo $pat
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| 188 | ## STDOUT:
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| 189 | (^[[:space:]]|[[:digit:]][[:digit:]])
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| 190 | ## END
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| 191 | 
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| 192 | #### literal ''
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| 193 | shopt -s ysh:all
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| 194 | var pat = ''
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| 195 | 
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| 196 | setvar pat = /'abc' 'def'/
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| 197 | echo $pat
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| 198 | 
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| 199 | #setvar pat = /'abc' '^ + * ?'/
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| 200 | #echo $pat
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| 201 | 
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| 202 | if ('abcde' ~ pat) { echo yes } else { echo no }
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| 203 | if ('abcdef' ~ pat) { echo yes } else { echo no }
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| 204 | 
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| 205 | ## STDOUT:
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| 206 | abcdef
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| 207 | no
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| 208 | yes
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| 209 | ## END
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| 210 | 
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| 211 | #### Single quotes and splicing (do what "foo $x ${x}" used to)
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| 212 | shopt -s ysh:all
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| 213 | var pat = ''
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| 214 | 
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| 215 | var x = 'x'
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| 216 | var y = 'y'
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| 217 | setvar pat = / @x @x 'abc' @x @y /
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| 218 | echo $pat
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| 219 | 
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| 220 | if ('xxabcx' ~ pat) { echo yes } else { echo no }
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| 221 | if ('xxabcxyf' ~ pat) { echo yes } else { echo no }
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| 222 | 
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| 223 | ## STDOUT:
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| 224 | xxabcxy
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| 225 | no
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| 226 | yes
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| 227 | ## END
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| 228 | 
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| 229 | #### @splice
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| 230 | shopt -s ysh:all
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| 231 | var d = /d+/;
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| 232 | var ip = / @d '.' @d '.' @d '.' @d /
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| 233 | echo $ip
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| 234 | if ('0.0.0.0' ~ ip) { echo yes } else { echo no }
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| 235 | if ('0.0.0' ~ ip) { echo yes } else { echo no }
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| 236 | ## STDOUT:
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| 237 | [[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+
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| 238 | yes
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| 239 | no
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| 240 | ## END
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| 241 | 
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| 242 | #### splice with capital letters
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| 243 | shopt -s ysh:all
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| 244 | var D = /d+/;
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| 245 | var ip = / D '.' D '.' D '.' D /
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| 246 | echo $ip
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| 247 | if ('0.0.0.0' ~ ip) { echo yes } else { echo no }
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| 248 | if ('0.0.0' ~ ip) { echo yes } else { echo no }
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| 249 | ## STDOUT:
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| 250 | [[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+
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| 251 | yes
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| 252 | no
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| 253 | ## END
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| 254 | 
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| 255 | #### Matching escaped tab character
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| 256 | shopt -s ysh:all
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| 257 | 
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| 258 | var lines = :| $'aa\tbb' $'cc\tdd' |
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| 259 | 
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| 260 | var pat = / ('a' [\t] 'b') /
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| 261 | write pat=$pat
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| 262 | write @lines | egrep $pat 
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| 263 | 
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| 264 | ## stdout-json: "pat=(a[\t]b)\naa\tbb\n"
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| 265 | 
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| 266 | #### Match unicode char
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| 267 | shopt -s ysh:all
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| 268 | var pat = / 'a' dot 'b' /
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| 269 | 
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| 270 | if ('axb' ~ pat ) { echo yes } else { echo no }
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| 271 | 
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| 272 | # mu character
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| 273 | if ($'a\xce\xbcb' ~ pat ) { echo yes } else { echo no }
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| 274 | 
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| 275 | if ('aZZb' ~ pat ) { echo yes } else { echo no }
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| 276 | ## STDOUT:
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| 277 | yes
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| 278 | yes
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| 279 | no
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| 280 | ## END
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| 281 | 
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| 282 | #### Match non-ASCII byte denoted using $'\xff' (TODO: LANG=C)
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| 283 | 
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| 284 | # NOTE: This pattern doesn't work with en_US.UTF-8.  I think the user should
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| 285 | # set LANG=C or shopt --unset libc_utf8.
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| 286 | 
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| 287 | shopt -s ysh:all
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| 288 | var pat = /[ $'\xff' ]/;
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| 289 | 
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| 290 | echo $pat | od -A n -t x1
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| 291 | if ($'\xff' ~ pat) { echo yes } else { echo no }
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| 292 | if ($'\xfe' ~ pat) { echo yes } else { echo no }
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| 293 | 
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| 294 | ## STDOUT:
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| 295 |  5b ff 5d 0a
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| 296 | yes
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| 297 | no
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| 298 | ## END
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| 299 | 
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| 300 | #### Match non-ASCII byte denoted using \xff
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| 301 | shopt -s ysh:all
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| 302 | var pat = /[ \xff ]/;
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| 303 | 
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| 304 | # Show what it translates to
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| 305 | echo $pat | od -A n -t x1
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| 306 | 
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| 307 | # TODO: This might require LANG=C to work
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| 308 | #if ($'\xff' ~ pat) { echo yes } else { echo no }
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| 309 | #if ($'\xfe' ~ pat) { echo yes } else { echo no }
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| 310 | 
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| 311 | ## STDOUT:
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| 312 |  5b ff 5d 0a
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| 313 | ## END
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| 314 | 
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| 315 | #### ERE can express Unicode escapes that are in the ASCII range
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| 316 | shopt -s ysh:all
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| 317 | var pat = /[ \u{7f} ]/;
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| 318 | 
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| 319 | echo $pat | od -A n -t x1
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| 320 | if ($'\x7f' ~ pat) { echo yes } else { echo no }
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| 321 | if ($'\x7e' ~ pat) { echo yes } else { echo no }
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| 322 | 
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| 323 | var pat2 = /[ \u{7f} ]/;
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| 324 | var pat3 = /[ \u{0007f} ]/;
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| 325 | test "$pat2" = "$pat3" && echo 'equal'
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| 326 | 
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| 327 | var range = / [ \u{70} - \u{7f} ] /
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| 328 | if ($'\x70' ~ range) { echo yes } else { echo no }
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| 329 | if ($'\x69' ~ range) { echo yes } else { echo no }
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| 330 | 
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| 331 | ## STDOUT:
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| 332 |  5b 7f 5d 0a
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| 333 | yes
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| 334 | no
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| 335 | equal
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| 336 | yes
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| 337 | no
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| 338 | ## END
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| 339 | 
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| 340 | #### ERE can't express higher Unicode escapes
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| 341 | shopt -s ysh:all
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| 342 | var pat2 = /[ \u{00} - \u{ff} ]/;
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| 343 | 
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| 344 | # This causes an error
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| 345 | echo $pat2
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| 346 | 
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| 347 | # This just prints it
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| 348 | = pat2
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| 349 | 
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| 350 | var pat1 = /[ \u{ff} ]/;
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| 351 | 
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| 352 | echo $pat1 | od -A n -t x1
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| 353 | if ($'\x7f' ~ pat) { echo yes } else { echo no }
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| 354 | if ($'\x7e' ~ pat) { echo yes } else { echo no }
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| 355 | 
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| 356 | ## status: 1
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| 357 | ## stdout-json: ""
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| 358 | 
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| 359 | #### non-ASCII bytes must be singleton terms, e.g. '\x7f\xff' is disallowed
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| 360 | var bytes = $'\x7f\xff'
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| 361 | var pat = / [ @bytes ] /
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| 362 | echo $pat
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| 363 | ## status: 1
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| 364 | ## stdout-json: ""
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| 365 | 
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| 366 | #### Matching escaped tab character
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| 367 | shopt -s ysh:all
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| 368 | 
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| 369 | # BUG: need C strings in array literal
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| 370 | var lines = :| $'aa\tbb' $'cc\tdd' |
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| 371 | 
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| 372 | var pat = / ('a' [\t] 'b') /
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| 373 | write pat=$pat
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| 374 | write @lines | egrep $pat 
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| 375 | 
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| 376 | ## stdout-json: "pat=(a[\t]b)\naa\tbb\n"
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| 377 | 
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| 378 | #### Repeated String Literal With Single Char
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| 379 | shopt -s ysh:all
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| 380 | 
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| 381 | var literal = 'f'
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| 382 | var pat = null
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| 383 | 
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| 384 | setvar pat = / %start @literal+ %end /
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| 385 | echo $pat
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| 386 | setvar pat = / %start (@literal)+ %end /
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| 387 | echo $pat
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| 388 | 
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| 389 | if ('fff' ~ pat) { echo yes }
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| 390 | if ('foo' !~ pat) { echo no }
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| 391 | 
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| 392 | ## STDOUT:
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| 393 | ^f+$
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| 394 | ^(f)+$
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| 395 | yes
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| 396 | no
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| 397 | ## END
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| 398 | 
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| 399 | #### Error when unparenthesized string of more than one character is repeated
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| 400 | shopt -s ysh:all
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| 401 | 
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| 402 | var literal = 'foo'
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| 403 | var pat = null
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| 404 | 
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| 405 | setvar pat = / %start @literal+ %end /
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| 406 | echo $pat
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| 407 | setvar pat = / %start (@literal)+ %end /
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| 408 | echo $pat
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| 409 | 
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| 410 | if ('foofoo' ~ pat) { echo yes }
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| 411 | if ('foof' !~ pat) { echo no }
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| 412 | 
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| 413 | ## status: 1
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| 414 | ## stdout-json: ""
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| 415 | 
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| 416 | #### Instead of $'foo\\bar' use 'foo' \\ 'bar'
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| 417 | shopt -s ysh:all
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| 418 | var pat = /'foo' \\ 'bar'/
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| 419 | echo $pat
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| 420 | 
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| 421 | if (r'foo\bar' ~ pat) { echo yes }
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| 422 | if (r'foo.bar' !~ pat) { echo no }
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| 423 | ## STDOUT:
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| 424 | foo\\bar
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| 425 | yes
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| 426 | no
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| 427 | ## END
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| 428 | 
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| 429 | #### Negation of Character Class ![a-z]
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| 430 | shopt -s ysh:all
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| 431 | 
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| 432 | var pat = / ![ a-z ] /
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| 433 | echo $pat
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| 434 | 
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| 435 | if ('0' ~ pat) { echo yes }
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| 436 | if ('a' !~ pat) { echo no }
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| 437 | 
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| 438 | ## STDOUT:
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| 439 | [^a-z]
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| 440 | yes
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| 441 | no
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| 442 | ## END
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| 443 | 
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| 444 | #### Posix and Perl class in class literals
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| 445 | shopt -s ysh:all
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| 446 | 
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| 447 | var pat = null
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| 448 | 
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| 449 | setvar pat = / [ space 'z' ] /
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| 450 | echo $pat
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| 451 | #setvar pat = / [ ~space 'z' ] /
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| 452 | #echo $pat
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| 453 | 
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| 454 | # PROBLEM: can't negate individual POSIX classes.  They would have to be a Perl
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| 455 | # class to be \D or \S.
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| 456 | # [[:space:]z] negates the whole thing!
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| 457 | # [^[:space:]]
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| 458 | 
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| 459 | setvar pat = / [ digit 'z' ] /
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| 460 | echo $pat
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| 461 | #setvar pat = / [ ~digit 'z' ] /
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| 462 | #echo $pat
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| 463 | 
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| 464 | ## STDOUT:
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| 465 | [[:space:]z]
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| 466 | [[:digit:]z]
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| 467 | ## END
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| 468 | 
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| 469 | #### [!d] can't be negated because it's a literal character
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| 470 | setvar pat = / [ !d 'z' ] /
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| 471 | echo $pat
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| 472 | ## status: 2
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| 473 | ## stdout-json: ""
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| 474 | 
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| 475 | #### [!digit] can't be negated in POSIX ERE (but yes in Perl)
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| 476 | var pat = null
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| 477 | setvar pat = / [ !digit 'z' ] /
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| 478 | echo $pat
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| 479 | ## status: 1
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| 480 | ## stdout-json: ""
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| 481 | 
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| 482 | #### Operator chars in char classes (bash-like)
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| 483 | 
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| 484 | pat='[-]'
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| 485 | [[ '-' =~ $pat ]] && echo hyphen
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| 486 | [[ '\' =~ $pat ]] && echo FAIL
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| 487 | 
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| 488 | pat='[\]'
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| 489 | [[ '\' =~ $pat ]] && echo backslash
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| 490 | [[ '-' =~ $pat ]] && echo FAIL
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| 491 | 
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| 492 | pat='[]]'
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| 493 | [[ ']' =~ $pat ]] && echo 'right bracket'
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| 494 | [[ '[' =~ $pat ]] && echo FAIL
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| 495 | 
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| 496 | pat='[[]'
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| 497 | [[ '[' =~ $pat ]] && echo 'left bracket'
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| 498 | [[ ']' =~ $pat ]] && echo FAIL
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| 499 | 
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| 500 | pat='[.]'
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| 501 | [[ '.' =~ $pat ]] && echo period
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| 502 | [[ '\' =~ $pat ]] && echo FAIL
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| 503 | 
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| 504 | pat='[\^]'
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| 505 | [[ '^' =~ $pat ]] && echo caret
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| 506 | [[ '\' =~ $pat ]] && echo 'no way to have [^]'
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| 507 | 
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| 508 | ## STDOUT:
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| 509 | hyphen
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| 510 | backslash
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| 511 | right bracket
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| 512 | left bracket
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| 513 | period
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| 514 | caret
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| 515 | no way to have [^]
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| 516 | ## END
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| 517 | 
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| 518 | #### Operator chars in char classes (eggex)
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| 519 | shopt --set ysh:upgrade
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| 520 | 
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| 521 | var pat = / ['-'] /
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| 522 | #echo PAT=$pat
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| 523 | if ('-' ~ pat) { echo hyphen }
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| 524 | if ($'\\' ~ pat) { echo FAIL }
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| 525 | 
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| 526 | var pat = / [ \\ ] /
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| 527 | [[ '\' =~ $pat ]] && echo backslash
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| 528 | [[ '-' =~ $pat ]] && echo FAIL
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| 529 | 
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| 530 | var pat = / [ ']' ] /
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| 531 | [[ ']' =~ $pat ]] && echo 'right bracket'
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| 532 | [[ '[' =~ $pat ]] && echo FAIL
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| 533 | 
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| 534 | var pat = / [ '[' ] /
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| 535 | [[ '[' =~ $pat ]] && echo 'left bracket'
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| 536 | [[ ']' =~ $pat ]] && echo FAIL
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| 537 | 
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| 538 | var pat = / [ '.' ] /
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| 539 | [[ '.' =~ $pat ]] && echo period
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| 540 | [[ '\' =~ $pat ]] && echo FAIL
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| 541 | 
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| 542 | var pat = / [ \\ '^' ] /
 | 
| 543 | [[ '^' =~ $pat ]] && echo caret
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| 544 | [[ '\' =~ $pat ]] && echo 'no way to have [^]'
 | 
| 545 | 
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| 546 | 
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| 547 | ## STDOUT:
 | 
| 548 | hyphen
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| 549 | backslash
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| 550 | right bracket
 | 
| 551 | left bracket
 | 
| 552 | period
 | 
| 553 | caret
 | 
| 554 | no way to have [^]
 | 
| 555 | ## END
 | 
| 556 | 
 | 
| 557 | #### Matching ] and \ and ' and " in character classes
 | 
| 558 | shopt -s ysh:all
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| 559 | 
 | 
| 560 | # BUG: need C strings in array literal
 | 
| 561 | var lines = :|
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| 562 |   'backslash \'
 | 
| 563 |   'rbracket ]'
 | 
| 564 |   'lbracket ['
 | 
| 565 |   "sq '"
 | 
| 566 |   'dq ""'
 | 
| 567 | |
 | 
| 568 | 
 | 
| 569 | # Weird GNU quirk: ] has to come first!
 | 
| 570 | # []abc] works.  But [abc\]] does NOT work.  Stupid rule!
 | 
| 571 | 
 | 
| 572 | var pat = / [ ']' \\ \' \" ] /
 | 
| 573 | write pat=$pat
 | 
| 574 | write @lines | egrep $pat 
 | 
| 575 | 
 | 
| 576 | ## STDOUT:
 | 
| 577 | pat=[]'"\\]
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| 578 | backslash \
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| 579 | rbracket ]
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| 580 | sq '
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| 581 | dq ""
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| 582 | ## END
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| 583 | 
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| 584 | #### Matching literal hyphen in character classes
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| 585 | shopt -s ysh:all
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| 586 | 
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| 587 | var literal = '-'
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| 588 | var pat = / [ 'a' 'b' @literal ] /
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| 589 | write pat=$pat
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| 590 | write 'c-d' 'ab' 'cd' | grep $pat
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| 591 | ## STDOUT:
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| 592 | pat=[ab-]
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| 593 | c-d
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| 594 | ab
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| 595 | ## END
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| 596 | 
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| 597 | #### Char class special: ^ - ] \
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| 598 | 
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| 599 | # See demo/ere-char-class-literals.sh
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| 600 | #
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| 601 | # \ is special because of gawk
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| 602 | 
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| 603 | shopt -s ysh:upgrade
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| 604 | 
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| 605 | 
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| 606 | # Note: single caret disalowed
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| 607 | var caret = / ['^' 'x'] /
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| 608 | echo caret=$caret
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| 609 | 
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| 610 | var caret2 = / [ \x5e 'x'] /
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| 611 | echo caret2=$caret2
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| 612 | 
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| 613 | var caret3 = / [ \u{5e} 'x'] /
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| 614 | echo caret3=$caret3
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| 615 | 
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| 616 | if ('x' ~ caret3) {
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| 617 |   echo 'match x'
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| 618 | }
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| 619 | if ('^' ~ caret3) {
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| 620 |   echo 'match ^'
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| 621 | }
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| 622 | 
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| 623 | echo ---
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| 624 | 
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| 625 | var hyphen = / ['a' '-' 'b'] /
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| 626 | echo hyphen=$hyphen
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| 627 | 
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| 628 | var hyphen2 = / ['a' \x2d 'b' ] /
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| 629 | echo hyphen2=$hyphen2
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| 630 | 
 | 
| 631 | if ('-' ~ hyphen2) {
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| 632 |   echo 'match -'
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| 633 | }
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| 634 | 
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| 635 | if ('a' ~ hyphen2) {
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| 636 |   echo 'match a'
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| 637 | }
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| 638 | 
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| 639 | if ('c' ~ hyphen2) {
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| 640 |   echo 'match c'
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| 641 | }
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| 642 | 
 | 
| 643 | echo ---
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| 644 | 
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| 645 | var rbracket = / [ '[' ']' ] /
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| 646 | echo rbracket=$rbracket
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| 647 | 
 | 
| 648 | var rbracket2 = / [ \x5b \x5d ] /
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| 649 | echo rbracket2=$rbracket2
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| 650 | 
 | 
| 651 | if ('[' ~ rbracket2) {
 | 
| 652 |   echo 'match ['
 | 
| 653 | }
 | 
| 654 | 
 | 
| 655 | if (']' ~ rbracket2) {
 | 
| 656 |   echo 'match ]'
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| 657 | }
 | 
| 658 | 
 | 
| 659 | echo ---
 | 
| 660 | 
 | 
| 661 | var backslash = / [ 'x' \\ 'n' ] /
 | 
| 662 | echo backslash=$backslash
 | 
| 663 | 
 | 
| 664 | var backslash2 = / [ 'x' \x5c 'n' ] /
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| 665 | echo backslash2=$backslash2
 | 
| 666 | 
 | 
| 667 | var backslash3 = / [ 'x' $'\\' 'n' ] /
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| 668 | echo backslash3=$backslash3
 | 
| 669 | 
 | 
| 670 | if ('x' ~ backslash3) {
 | 
| 671 |   echo 'match x'
 | 
| 672 | }
 | 
| 673 | 
 | 
| 674 | if ('n' ~ backslash3) {
 | 
| 675 |   echo 'match n'
 | 
| 676 | }
 | 
| 677 | 
 | 
| 678 | if ($'\\' ~ backslash3) {
 | 
| 679 |   echo 'match backslash'
 | 
| 680 | }
 | 
| 681 | 
 | 
| 682 | if ($'\n' ~ backslash3) {
 | 
| 683 |   echo 'match nnewline'
 | 
| 684 | }
 | 
| 685 | 
 | 
| 686 | 
 | 
| 687 | ## STDOUT:
 | 
| 688 | caret=[x^]
 | 
| 689 | caret2=[x^]
 | 
| 690 | caret3=[x^]
 | 
| 691 | match x
 | 
| 692 | match ^
 | 
| 693 | ---
 | 
| 694 | hyphen=[ab-]
 | 
| 695 | hyphen2=[ab-]
 | 
| 696 | match -
 | 
| 697 | match a
 | 
| 698 | ---
 | 
| 699 | rbracket=[][]
 | 
| 700 | rbracket2=[][]
 | 
| 701 | match [
 | 
| 702 | match ]
 | 
| 703 | ---
 | 
| 704 | backslash=[xn\\]
 | 
| 705 | backslash2=[xn\\]
 | 
| 706 | backslash3=[xn\\]
 | 
| 707 | match x
 | 
| 708 | match n
 | 
| 709 | match backslash
 | 
| 710 | ## END
 | 
| 711 | 
 |